UPDATED - House fire may be fatal

(BROCK TWP.) Family members of Jerry and Eve Cudahy are hoping for the best but fearing the worst as they held a roadside vigil Monday (Feb. 11) afternoon.
Investigators are continuing to comb through a mountain of smouldering rubble in a search of the couple, who lived at B570 Concession Road 2 Thorah. The home was levelled by a fire Sunday (Feb. 10) morning.
Nearly 36 hours later, investigators from the office of the Ontario Fire Marshal (OFM) have shed little light on the search.
As firefighters doused what little was left of the house, family members warmed themselves in a truck parked alongside the mud-lined road.
"They haven't told us anything," said Mr. Cudahy's brother, who declined to give his name.
"We were here almost all day yesterday and back again today. We still don't know what happened."
It's unclear who was in the home at the time of the fire.
"There is a person or persons unaccounted for," said Bryan Fischer, a fire investigation supervisor with the OFM.
"We're working with Brock Township Fire Department and the Durham Regional Police and searching the scene."
The blaze was reported after a motorist passing by noticed the house in flames. Brock Township firefighters were quick to respond after receiving the call around 7 a.m., Mr. Fischer said.
"When they arrived, the home was fully engulfed and partially collapsed."
Investigators have made no official comment on who the search efforts are focusing on.
As of 4 p.m. Monday, no bodies had been recovered.
A cause for the fire has yet to be determined.
"We're still working towards that," said Mr. Fischer.
Investigators will remain on the scene until Tuesday.
"There's no concrete timeline for an investigation like this. It depends on how things proceed," Mr. Fischer said.